Error scanning in flash memory

Abstract

Various embodiments include methods, apparatus, and systems to scan at least a portion of a memory device for potential errors when a condition for scanning is met. The condition may be dependent on one or more of a number of read operations, a number of write operations, time, and others. Other embodiments including additional methods, apparatus, and systems are disclosed.

1. An apparatus comprising:
 a circuit to set at least one condition to scan for errors in information stored in a memory array of a memory device, the condition to scan being based on a number of accesses to cells of the memory device, wherein the number of accesses comprises a number of read operations, and wherein the condition to scan is stored in a storage unit in the memory device, and the storage unit is located outside the memory array; and 
 a component to scan for errors in the information when the condition is met. 
 
     
     
       2. The apparatus of  claim 1 , wherein the condition for scanning is further based on an amount of time passed after the information was stored in the memory device. 
     
     
       3. The apparatus of  claim 1 , wherein the condition is met when the number of accesses to cells of the memory device is at least equal to a selected value. 
     
     
       4. The apparatus of  claim 1 , wherein the storage unit is configured to store a selected value, and wherein the condition is met when the number of read operations performed on only a selected portion of the memory device is at least equal to the selected value. 
     
     
       5. An apparatus comprising:
 a component to scan for errors in information stored in a memory array of a memory device when a condition for scanning is met, the condition for scanning being based on an amount of time passed after the information was stored in the memory device, wherein the condition to scan is stored in a storage unit in the memory device, and the storage unit is located outside the memory array. 
 
     
     
       6. The apparatus of  claim 5 , wherein the storage unit is configured to store a selected value, and wherein the condition is met when the amount of time is at least equal to the selected value. 
     
     
       7. The apparatus of  claim 5 , wherein the storage unit is configured to store an offset value, and wherein the component is to scan for errors at a location with an address based on the offset value. 
     
     
       8. The apparatus of  claim 5 , wherein the component comprises a real-time clock to determine a time interval to scan for errors. 
     
     
       9. A method comprising:
 scanning for errors in information stored in a memory array of a memory device when a condition for scanning is met, the condition for scanning is being based on a number of accesses to cells of the memory device, wherein the condition to scan is stored in a storage unit in the memory device, and the storage unit is located outside the memory array; and 
 counting a number of read operations in the memory device to determine whether the condition for scanning is met. 
 
     
     
       10. The method of  claim 9 , further comprising:
 comparing error correction code (ECC) data associated with the information when the information is read with ECC data associated with the information when the information was written into the cells to determine whether an error occurs. 
 
     
     
       11. The method of  claim 10 , further comprising:
 correcting at least one error bit in the information when the error occurs. 
 
     
     
       12. The method of  claim 9 , wherein the scanning is performed when the number of accesses is at least 1000. 
     
     
       13. A method comprising:
 scanning for errors in information stored in a memory array of a memory device when a condition for scanning is met, the condition for scanning being based on an amount of time passed after the information was stored in a storage unit in the memory device, wherein the condition to scan is stored in the memory device, and the storage unit is located outside the memory array. 
 
     
     
       14. The method of  claim 13 , wherein the condition for scanning is met when the amount of time is at least one day. 
     
     
       15. The method of  claim 13 , wherein scanning is performed at a selected time interval.